JPH07100309A - Filter - Google Patents

Abstract

PURPOSE:To provide an oil filter where the relative rotation between a case member and a cover member is prevented and the assembling and disassembling are easily and appropriately performed. CONSTITUTION:In the large diameter part of a case member 10, engaging projections 14 projecting towards the direction of its opening is formed, and also engaging parts 36 engaging with the engaging projections 14 are formed in a cover member 30. And the engaging part 36 of the cover part 30 is formed on the side edge of the cover member 30 as a notch or near the side edge as a through hole. And the engaging projections 14 of the case member 10 are engaged with the engaging parts 36 and the tip is made to extend outwards beyond the whole female screw part 53 of a tightening fixture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element exchange type filter device in which a filter element can be replaced.

[0002]

2. Description of the Related Art As a filter device of this type, a filter element is housed in a cylindrical case having a bottom, an opening of the case is covered with a set plate which is a cover member, and the case and the set plate are liquid-tight with a ring nut. A structure for fixing is already known (Japanese Patent Laid-Open No. 2-21910, etc.).

By removing the ring nut and opening the set plate, the filter element housed in the case can be replaced.

[0004]

However, since the conventional filter device is not provided with means (rotation preventing means) for restricting relative rotation between the case and the set plate before tightening with the ring nut, the case is not provided in the case. When the set plate is aligned and tightened with the ring nut, the case and the set plate rotate relative to each other with the rotation of the ring nut, and the case and the set plate are placed on the mating surface (sealing surface) or between them. There is a problem that the seal member is damaged and the sealing property is deteriorated.

The present invention has been made in view of the above points, and its object is to prevent relative rotation of the case member and the lid member to avoid deterioration of sealing performance, and to easily assemble and disassemble. The point is to provide a filter device that operates properly.

[0006]

In order to achieve the above object, the present invention has a bottomed cylindrical shape in which the open end at the tip of the body is made larger in diameter than the body. A case member, a filter member housed in the case member, and a lid member having a communication hole that covers the opening end of the body portion and communicates the inside and outside of the case member with a male screw portion on the outer peripheral side surface. A ring-shaped fastener having an internal thread portion on the inner peripheral surface thereof that can be screwed into the external thread portion of the lid member, and a narrow diameter portion having a smaller diameter than the large diameter portion of the case member In the device, the large-diameter portion of the case member is formed with an engaging protrusion that projects toward the opening direction, and the lid member is formed with an engaging portion that engages with the engaging protrusion. Also, the engaging portion of the lid member is provided as a notch on the side edge of the lid member or in the vicinity of the side edge. Formed as through holes, and a filter device is extended outward beyond the entire female threaded portion of the engaging projections is engaged the fastener tip of the case member to the engaging portion.

The large-diameter portion at the opening end of the case member indicates a portion which is expanded in the centrifugal direction or a cylindrical portion which includes the expanded diameter portion and extends in the opening direction at the maximum diameter of the expanded diameter portion. By engaging the engaging protrusions further protruding from the diameter portion with the engaging portions provided on the lid member, it is possible to prevent relative rotation between the case member and the lid member when tightening the fastener. As a result, it is possible to avoid deterioration of the sealing property.

Further, since the engaging protrusion of the case member engages with the engaging portion of the lid member and the tip extends outward beyond the entire female screw portion of the fastener, the engaging protrusion engages. It can be easily confirmed that the case member and the lid member are in a state in which the case member and the lid member cannot be rotated relative to each other by properly engaging the joint portion, and the assembling can be surely performed to improve the reliability of the sealing property. Since the tip of the engaging protrusion extends beyond the female screw portion of the fastener, the engaging protrusion does not catch on the female screw portion when the fastener is removed.

Further, the tip of the engaging projection of the case member is bent to be locked to the lid member so that it can be temporarily fixed, so that the assembling can be performed easily and appropriately.

Further, an engaging portion of the lid member is formed as a notch on a side edge of the lid member, and a female screw of a fastener is provided on an outer peripheral surface of a tip of an engaging protrusion of the case member engaging with the notch. By forming the tip relief part to prevent contact with the part, the female screw part is caught on the tip of the engaging protrusion of the case member when removing the fastener, and it is difficult to remove the engaging protrusion. It can be prevented from being deformed.

[0011]

EXAMPLES An example of the present invention shown in FIGS. 1 to 6 will be described below. FIG. 1 is a cross-sectional view of an automobile element exchange type oil filter device 1 of the present embodiment, FIG. 2 is a bottom view thereof, and FIG. 3 is an exploded cross-sectional view of the oil filter device 1.

A cartridge-type filter element 20 is housed in a cylindrical case 10 having a bottom, and an opening of the case 10 is covered by a set plate 30 as a lid member with an O-ring 18 as a sealing member interposed therebetween. A ring nut 50, which is a ring-shaped fastener, fixes the set plate 30 to the case 10.

The case 10 has a body portion 11 with one end portion having a bottom portion 12
Is closed, and the other open end is slightly expanded in diameter from the body portion 11 to form a flange-shaped large-diameter portion 13.
The peripheral wall has a crank-shaped cross section up to 13. As shown in FIG. 4, the large-diameter portion 13 has three engaging projections 14 projecting in the opening direction at equal intervals as shown in FIG. The lower ends of the engaging protrusions 14 are slightly bent inward to form locking claws 15.

Inside the case 10, as shown in FIGS. 1 and 3, a leaf spring 16 is fitted on the inner surface of the bottom portion 12 and extends obliquely and radially from the base portion at the center. The support arms 16a also extend radially from the leaf spring 16, and the support arms 16a
A can hold the leaf spring 16 by elastic force while bending along the inner surface from the bottom portion 12 to the body portion 11 of the case 10.

An annular guide member 17 is welded to the inner peripheral surface of the lower portion of the body portion 11 along a strip-shaped member, and the guide member 17 extends slightly downward from the body portion 11 and is large. A groove for positioning the O-ring 18 is formed between the groove 13 and the diameter portion 13.

The replaceable cartridge type filter element 20 has a filter 21 in which a filter paper is folded into a corrugated shape and formed into a cylindrical shape.
The lid 21 is covered with 22, 23, the inner peripheral surface is covered with a holder plate 24 having a large number of holes, and the filter 21 is held. The upper end opening of the cylindrical holder plate 24 is closed by a release valve 25.

The lower element plate 23 has an inner peripheral edge bent in a wavy shape and extending inward to form an opening 23a, and the opening 23a projects slightly downward.

On the other hand, the set plate 30 is shown in FIGS.
As shown in the figure, it has a substantially hollow disk shape, forms a horizontal bottom portion 32 that is slightly downward inward from the peripheral edge portion 31, and then reaches a cylindrical outlet 34 via a tapered portion 33 that is gently inclined upward. Forming a shape.

The outer diameter of the set plate 30 is slightly larger than the diameter of the large diameter portion 13 of the case 10, and the outer peripheral surface of the peripheral edge portion 31 has a male screw.
35 are engraved. Further, notches 36 into which the engaging protrusions 14 of the case 10 can be inserted are formed at three positions of the peripheral edge 31 which are spaced apart from each other at equal intervals.

In the tapered portion 33 of the set plate 30, six inflow ports 37 are formed at equal distances from the center at equal intervals. The cylindrical outlet 34 projects upward from the tapered portion 33, the outer diameter of which is substantially equal to the inner diameter of the guide portion 23a of the lower element plate 23 of the filter element 20, and the female screw 38 on the inner peripheral surface. Is engraved.

A rubber material valve 40 is fitted and held on the outer periphery of the projecting outlet 34 as shown in FIG.
Expands in the centrifugal direction from the fitting portion 40a to the outflow port 34 along the tapered portion 33, and the expansion portion 40b closes the inflow port 37 from above.

That is, the inflow of oil from the inflow port 37 is possible by the deformation of the expansion portion 40b, but constitutes a one-way valve that blocks the opposite flow. A recess 40c for receiving the guide portion 23a of the lower element plate 23 of the filter element 20 is formed in the fitting portion 40a of the valve 40.

From the horizontal bottom 32 of the set plate 30 to the periphery
A ring-shaped seal plate along the lower surface of 31
41 is attached, and the portion attached to the horizontal bottom portion 32 holds the ring-shaped sealing member 42, and the outer peripheral edge 41a of the portion along the peripheral edge portion 31 partially covers the notch 36.

The ring nut 50 has an L-shaped cross section in which one end of the cylinder is curved toward the center side, and the inner diameter of the cylindrical portion 51 is slightly larger than the outer diameter of the large diameter portion 13 of the case 10, The inner diameter of the narrow-diameter portion 52 curved to be slightly larger than the outer diameter of the body portion 11 of the case 10 can penetrate the body portion 11, but cannot penetrate the large-diameter portion 13.

The set plate 30 is provided on the inner peripheral surface of the cylindrical portion 51.
A female screw 53 that is screwed into a male screw 35 provided on the outer periphery of the set plate 30 is formed from the back side by the thickness of the set plate 30, and a tapered guide portion 54 is formed from the opening end to the female screw 53 portion. .

A method of assembling the oil filter device 1 of the present embodiment having the above structure will be described below. First, the O-ring 18 is fitted into the groove formed by the large diameter portion 13 and the guide member 17 with the opening of the case 10 facing upward, and the leaf spring 16 is inserted into the case 10 to support the support arm 16a on the bottom portion 12. To bend and hold it in place.

When the filter element 20 is inserted into the case 10 with the release valve 25 side first, the element plate 22 comes into contact with the tip of the leaf spring 16 and elastically deforms the leaf spring 16 to remove the filter element 20 in the removing direction. Will be urged.

Next, the opening of the case 10 is covered with the set plate 30. At that time, the three notches 36 formed in the peripheral portion 31 of the set plate 30 are aligned with the three engaging protrusions 14 of the large-diameter portion 13 of the case 10, and the engaging protrusions 14 are fitted into the notches 36. To get in.

First, the outlet 34 protruding in the center of the set plate 30 is the element plate of the filter element 20.
23 is inserted into the opening 23a. When the outflow port 34 is inserted into the opening portion 23a and the opening portion 23a is fitted into the recess 40c along the outflow port 34 of the valve 40, the filter element 20 becomes the case 10.
The engaging projection 14 of the case 10 is inserted into the notch 36 of the set plate 30.

At this time, the tip locking claws 15 of the engaging protrusions 14 are
The outer peripheral edge of the seal plate 41 that partially hangs on the notch 36
The outer peripheral edge 41a is elastically deformed by abutting against the outer peripheral edge 41a.
The outer peripheral edge 41a restored beyond 41a can be locked from the outside, and the set plate 30 can be temporarily fixed to the case 10.

As described above, since the engaging protrusion 14 of the case 10 projects outward from the notch 36 of the set plate 30,
Whether the engaging protrusion 14 is correctly inserted in the notch 36 can be easily checked by eye or even by touching with hands, and it is possible to prevent the case 10 and the set plate 30 from being relatively rotated by mistake. As a result, damage to the O-ring 18 and the like can be prevented, and the reliability of the sealing property can be improved.

In this temporarily fixed state, the large diameter portion of the case 10
The O-ring 18 fitted in 13 is the peripheral edge 31 of the set plate 30.
The space surrounded by the case 10 and the set plate 30 is defined from the outside by being pressed by the outer side, and the opening 23a of the element plate 23 below the filter element 20 is fitted into the recess 40c of the valve 40. Tapered part of the set plate 30
The base end fitting portion 40a of the valve 40 is sandwiched between the valve 33 and the inlet 33
The outside of the filter 21 communicating with 37 and the inside of the filter 21 communicating with the outlet 34 are blocked.

Next, the guide portion 54 of the ring nut 50 is attached to the case 10
Ring nut 50 on the bottom of the case 10
When inserted from the side, the ring nut is guided by the guide part 54.
50 is placed on the outside of the large diameter portion 13, and the guide portion 54 is first inserted into the notch 36 of the peripheral edge portion 31 of the set plate 30 to insert the female screw 53 on the inner periphery of the cylindrical portion 51 of the ring nut 50. The position can be easily and reliably aligned with the male screw 35 on the set plate 30 side.

Then, the case 10 is fixedly supported, the ring nut 50 is rotated, and the female screw 53 is attached to the male screw of the set plate 30.
Screw to 35. When the case 10 is fixed, the set plate 30 is also integrally fixed by the engagement between the engaging protrusion 14 and the notch 36, so that the set plate 30 does not idle even when the ring nut 50 rotates. It is fixed and screwed smoothly.

The set plate 30 is screwed into the ring nut 50 by screwing the male screw 35 of the set plate 30 and the female screw 53 of the ring nut 50, while the case 10 has its large diameter portion 13 ringed. Since the narrow diameter portion 52 of the nut 50 prevents the nut 50 from being penetrated and is pressed, the set plate 30 is screwed into the ring nut 50 so as to push the filter element 20 into the case 10.

Therefore, the clamping pressure of the fitting portion 40a of the valve 40 is increased, and the outer side and the inner side of the filter 21 are surely shut off,
Further, the O-ring 18 is also clamped more strongly to enhance the sealing property.

The oil filter device 1 thus assembled is attached to the engine of the automobile. A cylindrical male screw projects from the mounting surface on the engine side, and a female screw 38 on the inner periphery of the outflow port 34 of the set plate 30 is screwed into the screw. At this time, if the case 10 is rotated, the set plate 30
Can rotate together and be easily screwed together.

On the contrary, the case 10 is rotated in the reverse direction to remove the oil filter 1 from the engine side mounting portion, and the ring nut
Rotate 50 to unscrew the set plate 30 Case 10
If the temporary fixing to the outer peripheral edge 41a of the seal plate 41 by the locking claw 15 is removed, it can be disassembled as shown in FIG.
Only the filter element 20 can be replaced easily.

When the ring nut 50 is unscrewed,
The tip locking claw 15 of the engaging projection 14 on the case 10 side protrudes outward from the female screw 53 on the ring nut 50 side and the tip faces inward, so that the female screw 53 when unscrewing is The ring nut 50 can be smoothly removed without being caught by the tip of the engaging protrusion 14.

Even in the structure in which the female screw 53 of the ring nut 50 is at the tip position of the engaging protrusion 14 in the screwed state, if the tip of the engaging protrusion 14 bends inward and escapes, When the nut 50 is removed, the female screw 53 does not get caught on the engaging protrusion 14.

As described above, in this embodiment, the case 10 and the set plate 30 are prevented from rotating relative to each other by the engagement between the engaging protrusion 14 of the case 10 and the notch 36 of the set plate 30. Since it rotates, the set plate 30 does not idle around the case 10 when the ring nut 50 is attached / removed or the oil filter 1 is attached / removed to / from the engine mounting side, and the attachment / detachment is easy.

Since the case 10 and the set plate 30 do not rotate relative to each other, the O-ring 18 and the valve sandwiched between
It is possible to secure high sealing performance without damaging 40.

The case 10 and the set plate 30 are temporarily fixed by temporarily locking the locking claws 15 of the engaging protrusions 14 to the outer peripheral edge 41a of the seal plate 41 attached to the lower surface of the set plate 30. Therefore, the assembly is made easier. It is possible to easily remove the temporary fixing between the case 10 and the set plate 30 by elastically deforming the outer peripheral edge 41a of the seal plate 41.

Further, since the tip of the engaging protrusion 14 projects outward from the female screw 53, the female screw 53 does not catch on the engaging protrusion 14 even when the ring nut 50 is removed.

Another embodiment will be described with reference to FIG. In the same example, the notch 62 of the peripheral edge portion 61 of the set plate 60 has an oblique taper surface with a large opening on the upper side and a small opening on the lower side.
Forming 63. The distance from the center of the center height position of the tapered surface 63 is substantially equal to the distance from the center of the tip locking claw 15 of the engaging protrusion 14 of the case 10.

Accordingly, when the set plate 60 is temporarily fixed to the case 10, the engaging protrusion 14 and the notch 62 are aligned with each other, and the engaging protrusion 14 is inserted into the notch 62.
The tip locking pawl 15 of 14 is brought into sliding contact with the tapered surface 63 of the notch 62,
The engaging projection 14 can be slightly elastically deformed and expanded in the centrifugal direction, and the engaging claw 15 can be engaged by riding over the lower edge of the tapered surface 63.

As described above, the case 10 and the set plate 60
Temporary fastening can be performed easily, and subsequent assembling work is also easy in the temporarily fastened state. The seal plate 64 attached to the lower surface of the set plate 60 in the same example does not have the outer peripheral edge reaching the notch 62, and the locking claw 15 of the engaging protrusion 14 has the set plate 60.
It is directly locked to. The members other than the set plate 60 and the seal plate 64 are the same as those in the above-described embodiment, and the same reference numerals are used.

Next, a modification of the above embodiment is shown in FIG. The set plate 70 of the same example has a smooth curved surface by taking the corner of the upper edge of the outer peripheral surface 73 of the notch 72 of the peripheral portion 71,
When the engaging protrusion 14 of the case 10 is inserted into the notch 72 of the set plate 70, the tip locking claw 15 of the engaging protrusion 14 slides along the curved surface of the upper edge of the outer peripheral surface 73 to engage the engaging protrusion. 14 is inserted into the notch 72 in a slightly expanded state, the locking claw 15 is locked to the lower edge of the outer peripheral surface 73, and the set plate 70 can be temporarily fixed. The same example can also facilitate the assembly. Further, since the O-ring 18 does not contact the corner of the upper edge of the outer peripheral surface 73 of the cutout 72, the durability of the seal is improved.

Next, a modified example of temporary fixing of the case and the set plate will be described with reference to FIG. In the case 80 of the same example, the engaging projection 81 is shorter than that of the above-mentioned embodiment, and the tip is bent inward to form the locking claw 82.

Further, the notch of the peripheral portion 84 of the set plate 83
85 has a protrusion 86 whose outer periphery projects upward in the centrifugal direction, and the engagement protrusion 81 inserted into the notch 85 has a locking claw at the tip.
82 is locked to the projection 86 and is temporarily fixed.

In the same example, the tip of the engaging projection 81 is housed in the notch 85 and does not project outward. Although the engaging projection 81 is shorter than the above-described embodiment and the tip of the engaging projection 81 is located at the position of the female screw 53 of the ring nut 50 as shown in FIG.
Since the tip of the engaging projection 81 is bent inward to form the locking claw 82, the tip of the engaging projection 81 does not get caught by the female screw 53 when the ring nut 50 is removed, and the ring nut smoothly. 50 can be removed.

The notch 85 of the set plate 83 into which the engaging projection 81 is inserted when temporarily fixing as in the same example does not necessarily have to be a notch penetrating vertically, but a shape in which the lower part of the notch is closed. May be

In the above embodiment, the peripheral edge of the set plate is notched. However, a locking hole may be provided in the peripheral edge instead of the notch, and the locking hole is not a through hole and the bottom is closed. But it's okay.

Further, as shown in FIG. 9, when the tip of the engaging projection 81 is located at the position of the female screw 53 of the ring nut 50 in the assembled state, the tip escape portion is formed by bending the tip inward in the same example. Although it is formed to avoid contact with the female screw 53,
It is also possible to avoid contact with the female screw by forming a tip relief portion by obliquely notching the outer corner of the tip of the engaging projection and thinning it without bending the tip.

[0055]

According to the first aspect of the present invention, the engaging protrusion formed on the opening end of the case member engages with the engaging portion provided on the lid member, so that the case can be tightened when the fastener is tightened. It is possible to prevent relative rotation between the member and the lid member, and as a result, it is possible to avoid deterioration in sealing performance.

Further, since the engaging protrusion of the case member engages with the engaging portion of the lid member and the tip is extended outward beyond the entire female screw portion of the fastener, the engaging protrusion is It is possible to easily confirm that the case member and the lid member are in the state in which the case member and the lid member cannot be rotated relative to each other by properly engaging the engaging portion, and the assembling can be surely performed to improve the reliability of the sealing property. Further, when the fastener is removed, the female screw portion does not get caught on the engaging projection portion, and the assembly and disassembly can be smoothly performed.

According to the second aspect of the invention, the tip of the engaging projection of the case member is bent and locked to the lid member so as to be temporarily fixed, whereby the assembly is easily and appropriately performed.

According to the third invention, the engaging portion of the lid member is formed as a notch on the side edge of the lid member, and the outer periphery of the tip of the engaging projection of the case member engaging with the notch. By forming a tip relief portion on the surface to prevent contact with the female screw portion of the fastener, the female screw portion is caught on the tip of the engaging protrusion of the case member when the fastener is removed, which makes removal difficult. Or, it is possible to prevent the tip of the engaging protrusion from being deformed.

[Brief description of drawings]

FIG. 1 is a sectional view of an oil filter device according to an embodiment of the present invention.

FIG. 2 is a bottom view of the same.

FIG. 3 is an exploded sectional view of the device.

FIG. 4 is a perspective view of a case of the device.

FIG. 5 is a perspective view of a set plate of the apparatus.

FIG. 6 is an enlarged sectional view of a main part.

FIG. 7 is an enlarged cross-sectional view of a main part of another embodiment.

FIG. 8 is an enlarged cross-sectional view of a main part of another embodiment.

FIG. 9 is an enlarged sectional view of a main part of still another embodiment.

[Explanation of symbols]

1 ... Oil filter device, 10 ... Case, 11 ... Body part, 12 ...
Bottom part, 13 ... Large diameter part, 14 ... Engaging projection part, 15 ... Engaging claw, 16 ...
Leaf spring, 17 ... guide member, 18 ... O-ring, 20 ... filter element, 21 ... filter, 22, 23 ... element plate, 24 ... holder plate, 25 ... release valve, 30 ...
Set plate, 31 ... Peripheral part, 32 ... Horizontal bottom part, 33 ... Tapered part, 34 ... Outlet port, 35 ... Male screw, 36 ... Notch, 37 ... Inlet port, 38 ... Female screw, 40 ... Valve, 41 ... Seal Plate, 50
… Ring nut, 51… Cylindrical part, 52… Narrow diameter part, 53… Female screw, 54… Induction part, 60… Set plate, 61… Peripheral part, 62
... notch, 63 ... taper surface, 64 ... seal plate, 70 ... set plate, 71 ... peripheral part, 72 ... notch, 73 ... outer peripheral surface,
80 ... Case, 81 ... Engaging protrusion, 82 ... Locking claw, 83 ... Set plate, 84 ... Peripheral portion, 85 ... Notch, 86 ... Projection.

Claims (3)

[Claims] 1. A bottomed cylindrical case member having an open end at the tip of the body portion that has a larger diameter than that of the body portion, a filter medium housed in the case member, and the body portion. A lid member having a communication hole that covers the inside and outside of the case member while covering the opening end of the lid member, and a male screw portion on the outer peripheral side surface,
A filter device having an inner peripheral surface having a female screw portion that can be screwed into the male screw portion of the lid member and a ring-shaped fastener having a narrow diameter portion smaller than the large diameter portion of the case member. In the large-diameter portion of the case member, the engaging protrusion that protrudes toward the opening direction is formed, the lid member is formed with an engaging portion that engages with the engaging protrusion, The engaging portion of the member is formed as a notch in the side edge of the lid member or as a through hole in the vicinity of the side edge, and the engaging protrusion of the case member engages with the engaging portion and the tip of the fastener is formed. A filter device characterized in that it extends outward beyond the entire female screw portion. 2. A bottomed cylindrical case member having an open end at the tip of the body portion which has a larger diameter than that of the body portion, a filter medium housed in the case member, and the body portion. A lid member having a communication hole that covers the inside and outside of the case member while covering the opening end of the lid member, and a male screw portion on the outer peripheral side surface,
A filter device having an inner peripheral surface having a female screw portion that can be screwed into the male screw portion of the lid member and a ring-shaped fastener having a narrow diameter portion smaller than the large diameter portion of the case member. In the large diameter portion of the case member, an engaging protrusion that protrudes toward the opening direction is formed, and in the lid member, an engaging portion that engages with the engaging protrusion is formed, and A filter device, wherein a tip of an engaging protrusion of the case member is bent to be temporarily fixed to the lid member. 3. A bottomed cylindrical case member having an open end at the front end of the body portion which has a larger diameter than that of the body portion, a filter medium housed in the case member, and the body portion. A lid member having a communication hole that covers the inside and outside of the case member while covering the opening end of the lid member, and a male screw portion on the outer peripheral side surface,
A filter device having an inner peripheral surface having a female screw portion that can be screwed into the male screw portion of the lid member and a ring-shaped fastener having a narrow diameter portion smaller than the large diameter portion of the case member. In the large diameter portion of the case member, an engaging protrusion that protrudes toward the opening direction is formed, and in the lid member, an engaging portion that engages with the engaging protrusion is formed, and The engaging portion of the lid member is formed as a notch on the side edge of the lid member, and the outer peripheral surface of the tip of the engaging protrusion of the case member engaging with the notch is formed with the female screw portion of the fastener. A filter device having a tip relief formed to prevent contact.